The present invention relates in general to printed circuit board conveyor apparatus. More particularly, the invention relates to an improved form of holder for a printed circuit board as used in such apparatus.
Printed circuit boards have come into increasing use in the electronics industry. Particularly with miniaturization, the need for high speed efficient and accurate processing of printed circuit board components has increased. Often the circuit board components start with a base sheet of insulating material which may have bound to one or both sides thereof a layer of copper. The base is often called a substrate and can take the form of epoxy, glass or various polymeric materials.
The processing steps on printed circuit board components are often carried out in conveyor apparatus along horizontal paths where various treating stations expose the board components to processing. These steps can be developing, rinsing-etching, rinsing-resist stripping-rinsing, black oxide coating, drying and the like.
Often apparatus for conveying and treating the printed circuit boards take up substantial manufacturing area space. Lines can run from ten to thirty feet in horizontal space. Problems sometimes arise in spray treating as in developing, etching, washing and stripping. The boards at stages of manufacture are often non-rigid and tend to wiggle when exposed to spray baths and the like. This can lead to non-uniformity in application of sprayed materials. The printed circuit board apparatus presented in the aforementioned copending application Ser. No. 455,956 for the most part overcomes all of the aforementioned problems but it is the intent of the present invention to provide in particular, a holder forming part of the conveying apparatus and which has improved stability so as to enable the proper carrying out of the processing steps to be conducted on the printed circuit board.